Three tools cover a bolted joint end to end: the torque calculator sizes the tightening torque and preload, the weight calculator totals the complete fastener set, and the shear calculator checks the side-load limit state. Every formula is printed on the page and every result updates live — this page maps which tool answers which question, and how they chain together.
The flagship tool. Enter bolt material, diameter, thread series, and lubrication to get the tightening torque for a required clamping force — or run it in reverse from a known torque. Includes the K-constant table, a computed torque chart at 75% preload, a grade strength check with pass/fail verdict, and an elongation estimate from the grip length.
Open the Torque CalculatorWeigh the complete fastener set, not just the bolt: hex bolt plus hex nut, heavy hex nut, and washer options, each with its own quantity. Per-piece and total weights in both kg and lb, computed from nominal ASME geometry at steel density — ready for shipping quotes, rigging picks, and bills of material.
Open the Weight CalculatorCheck the shear side of the joint with interactive sliders: bolt count, diameter, single or double shear configuration, and grade-based allowable stress (0.62·Fu threads excluded, 0.48·Fu included). Live pass/fail verdict with a safety-factor control and a visual joint diagram.
Open the Shear Calculator
One joint, four stepsPhoto: UnsplashWhy the order matters
The strength check and the shear check answer different failure modes — tension in the shank versus load across it. A joint can pass one and fail the other, which is why the tools stay separate instead of merging into a single unverifiable verdict.
A real assembly moves through the toolset in the same order the questions arrive — each step hands its output to the next as an input.
Start from the clamp load the joint needs — a gasket seating load, a friction-grip requirement, or simply the 75%-of-yield default for a reusable connection. Enter the diameter, grade, and the K factor that matches your coating and lubrication; the tool returns the torque target plus the min/max assembly band friction scatter and tool accuracy actually produce.
The strength check inside the torque tool verifies the same answer from the bolt's side: tensile stress area for the thread series you selected, preload as a percentage of the grade's yield, and a utilization ratio with a pass/fail verdict. If the wrench setting asks the bolt for more than it should give, this is where it shows.
Where the joint carries load across the shank — brackets, lugs, lap joints — the shear calculator checks the limit state: single or double shear, bolt count, grade-based allowable stress following the AISC 0.62·Fu / 0.48·Fu convention, and a safety-factor slider that turns a bare PASS into a defensible margin.
Before the order goes out, the weight calculator totals the hardware: bolt, nut, and washer at real quantities, in kilograms and pounds, from ASME nominal geometry. The number that reaches the freight quote is the number the truck actually carries.
Match the task in front of you to the tool that answers it — what you enter, what you get back.
| Your Task | Tool | You Enter | You Get |
|---|---|---|---|
| Set a torque wrench for a required clamp load | Torque | Diameter, grade, K factor or finish & lubrication, target force | Tightening torque plus the min/max assembly range |
| Check a torque spec against the bolt's limits | Torque (strength check) | Torque, diameter, grade, thread series | Stress area, preload, utilization % and PASS/FAIL |
| Check bolts carrying a side load | Shear | Bolt count, diameter, shear planes, applied load, safety factor | Allowable vs. actual stress with a live margin |
| Quote freight or rigging for a fastener order | Weight | Bolt, nut, and washer sizes with quantities | Per-piece and set totals in kg and lb |
| Compare two fastener options before buying | Torque + Weight | Each candidate's grade, size, and set quantity | Preload capability and shipping weight, side by side |
Every registered calculator on the site — each one narrow, deep, and built on the same published engineering data as the flagship torque tool.
The three tools look different because they answer different questions — but they share one engineering philosophy. Six properties you will find in all of them.
No submit button, no waiting. Change the diameter and every dependent output — stress area, torque band, utilization — recalculates in the same instant you type.
The unit toggle switches every input and output together: mm ↔ inches, N ↔ lbf, N·m ↔ lb-ft, kg ↔ lb. Values you already entered convert with the switch, so the physics never changes behind your back.
Every tool documents its own method on the page — the torque equation, the stress-area formulas, the weight model — so any result can be re-derived by hand or audited by a reviewer.
Grades from ISO 898-1 and SAE J429, thread geometry from ISO 68-1 / ASME B1.1, hardware proportions from ASME B18.2.1/B18.2.2, shear allowables from the AISC convention. No invented constants.
Switching between coarse and fine series updates the tensile stress area — and with it the strength check — automatically. Sizes without a fine variant say so instead of guessing.
All math runs locally in your browser — nothing is uploaded or saved. When you need the number elsewhere, a copy button puts a formatted summary on your clipboard in one tap.
The tools handle the arithmetic; three inputs have to come from the real joint, because no formula can see them from here. Bring these, and the outputs are as honest as the method behind them.
Read the head marking — 8.8, 10.9, Grade 5, Grade 8 — rather than assuming from where the bolt came from. An 8.8 habit meeting a 10.9 bolt leaves a joint loose at its rated load; the reverse overloads the smaller fastener. The strength check is only as true as the grade you select.
Dry, zinc-plated, lightly oiled, anti-seize — the K factor follows the coating and lubrication, and it moves the answer more than any other input. The same bolt can need roughly 30% more torque dry than oiled, which is why the lubrication selector sits beside the diameter, not buried in an advanced panel.
Burrs under the head, galled threads, and embedment are invisible to every calculator. Plan a joint check — torque audit, angle check, or simply a re-torque after settling — so the assembled joint, not the estimate, has the final word on the preload achieved.
Bring those three and the calculators will carry the rest — the stress areas, the grade minimums, the geometry tables, the scatter band — all printed on the page where you can audit them. The disclaimer spells out where the tool’s job ends and the qualified engineer’s begins.
How the tools run, which standards the data follows, and how the three calculators fit together.
Pick the bolt material, set the diameter, enter the clamping force — and watch the torque, assembly range, and strength verdict line up in real time.
Open the Bolt Torque Calculator